Motivic Pattern Classification of Music Audio Signals Combining Residual and LSTM Networks

Motivic pattern classification from music audio recordings is a challenging task. More so in the case of a cappella flamenco cantes, characterized by complex melodic variations, pitch instability, timbre changes, extreme vibrato oscillations, microtonal ornamentations, and noisy conditions of the recordings. Convolutional Neural Networks (CNN) have proven to be very effective algorithms in image classification. Recent work in large-scale audio classification has shown that CNN architectures, originally developed for image problems, can be applied successfully to audio event recognition and classification with little or no modifications to the networks. In this paper, CNN architectures are tested in a more nuanced problem: flamenco cantes intra-style classification using small motivic patterns. A new architecture is proposed that uses the advantages of residual CNN as feature extractors, and a bidirectional LSTM layer to exploit the sequential nature of musical audio data. We present a full end-to-end pipeline for audio music classification that includes a sequential pattern mining technique and a contour simplification method to extract relevant motifs from audio recordings. Mel-spectrograms of the extracted motifs are then used as the input for the different architectures tested. We investigate the usefulness of motivic patterns for the automatic classification of music recordings and the effect of the length of the audio and corpus size on the overall classification accuracy. Results show a relative accuracy improvement of up to 20.4% when CNN architectures are trained using acoustic representations from motivic patterns

Maths, Computation and Flamenco: overview and challenges

Flamenco is a rich performance-oriented art music genre from Southern Spain which attracts a growing community of aficionados around the globe. Due to its improvisational and expressive nature, its unique musical characteristics, and the fact that the genre is largely undocumented, flamenco poses a number of interesting mathematical and computational challenges. Most existing approaches in Musical Information Retrieval (MIR) were developed in the context of popular or classical music and do often not generalize well to non-Western music traditions, in particular when the underlying music theoretical assumptions do not hold for these genres. Over the recent decade, a number of computational problems related to the automatic analysis of flamenco music have been defined and several methods addressing a variety of musical aspects have been proposed. This paper provides an overview of the challenges which arise in the context of computational analysis of flamenco music and outlines an overview of existing approaches

Detection of Melodic Patterns in Automatic Transcriptions of Flamenco Singing

The spontaneous expressive interpretation of melodic templates is a fundamental concept in flamenco music. Consequently, the automatic detection of such patterns in music collections sets the basis for a number of challenging analysis and retrieval tasks. We present a novel algorithm for the automatic detection of manually defined melodies within a corpus of automatic transcriptions of flamenco recordings. We evaluate the performance on the example of five characteristic patterns from the fandango de Valverde style and demonstrate that the algorithm is capable of retrieving ornamented instances of query patterns. Furthermore, we discuss limitations, possible extensions and applications of the proposed system

Proceedings of the 6th International Workshop on Folk Music Analysis, 15-17 June, 2016

The Folk Music Analysis Workshop brings together computational music analysis and ethnomusicology. Both symbolic and audio representations of music are considered, with a broad range of scientific approaches being applied (signal processing, graph theory, deep learning). The workshop features a range of interesting talks from international researchers in areas such as Indian classical music, Iranian singing, Ottoman-Turkish Makam music scores, Flamenco singing, Irish traditional music, Georgian traditional music and Dutch folk songs. Invited guest speakers were Anja Volk, Utrecht University and Peter Browne, Technological University Dublin

Flamenco music information retrieval.

El flamenco, un género musical centrado en la improvisación y la espontaneidad, tiene su origen en el sur de España y atrae a una creciente comunidad de aficionados de países de todo el mundo. El aumento constante y la accesibilidad a colecciones digitales de flamenco, en archivos de música y plataformas online, exige el desarrollo de métodos de análisis y descripción computacionales con el fin de indexar y analizar el contenido musical de manera automática. Music Information Retrieval (MIR) es un área de investigación multidisciplinaria dedicada a la extracción automática de información musical desde grabaciones de audio y partituras. Sin embargo, la gran mayoría de las herramientas existentes se dirigen a la música clásica y la música popular occidental y, a menudo, no se generalizan bien a las tradiciones musicales no occidentales, particularmente cuando las suposiciones relacionadas con la teoría musical no son válidas para estos géneros. Por otro lado, las características y los conceptos musicales específicos de una tradición musical pueden implicar nuevos desafíos computacionales, para los cuales no existen métodos adecuados. Esta tesis enfoca estas limitaciones existentes en el área abordando varios desafíos computacionales que surgen en el contexto de la música flamenca. Con este fin, se realizan una serie de contribuciones en forma de algoritmos novedosos, evaluaciones comparativas y estudios basados en datos, dirigidos a varias dimensiones musicales y que abarcan varias subáreas de ingeniería, matemática computacional, estadística, optimización y musicología computacional. Una particularidad del género, que influye enormemente en el trabajo presentado en esta tesis, es la ausencia de partituras para el cante flamenco. En consecuencia, los métodos computacionales deben basarse únicamente en el análisis de grabaciones, o de transcripciones extraídas automáticamente, lo que genera una colección de nuevos problemas computacionales. Un aspecto clave del flamenco es la presencia de patrones melódicos recurrentes, que esán sujetos a variación y ornamentación durante su interpretación. Desde la perspectiva computacional, identificamos tres tareas relacionadas a esta característica que se abordan en esta tesis: la clasificación por melodía, la búsqueda de secuencias melódicas y la extracción de patrones melódicos. Además, nos acercamos a la tarea de la detección no supervisada de frases melódicas repetidas y exploramos el uso de métodos de deep learning para la identificación de cantaores en grabaciones de video y la segmentación estructural de grabaciones de audio. Finalmente, demostramos en un estudio de minería de datos, cómo una exploración de anotaciones extraídas de manera automática de un corpus amplio de grabaciones nos ayuda a descubrir correlaciones interesantes y asimilar conocimientos sobre este género mayormente indocumentado.Flamenco is a rich performance-oriented art music genre from Southern Spain, which attracts a growing community of aficionados around the globe. The constantly increasing number of digitally available flamenco recordings in music archives, video sharing platforms and online music services calls for the development of genre-specific description and analysis methods, capable of automatically indexing and examining these collections in a content-driven manner. Music Information Retrieval is a multi-disciplinary research area dedicated to the automatic extraction of musical information from audio recordings and scores. Most existing approaches were however developed in the context of popular or classical music and do often not generalise well to non-Western music traditions, in particular when the underlying music theoretical assumptions do not hold for these genres. The specific characteristics and concepts of a music tradition can furthermore imply newcomputational challenges, for which no suitable methods exist. This thesis addresses these current shortcomings of Music Information Retrieval by tackling several computational challenge which arise in the context of flamenco music. To this end, a number of contributions to the field are made in form of novel algorithms, comparative evaluations and data-driven studies, directed at various musical dimensions and encompassing several sub-areas of computer science, computational mathematics, statistics, optimisation and computational musicology. A particularity of flamenco, which immensely shapes the work presented in this thesis, is the absence of written scores. Consequently, computational approaches can solely rely on the direct analysis of raw audio recordings or automatically extracted transcriptions, and this restriction generates set of new computational challenges. A key aspect of flamenco is the presence of reoccurring melodic templates, which are subject to heavy variation during performance. From a computational perspective, we identify three tasks related to this characteristic - melody classification, melody retrieval and melodic template extraction - which are addressed in this thesis. We furthermore approach the task of detecting repeated sung phrases in an unsupervised manner and explore the use of deep learning methods for image-based singer identification in flamenco videos and structural segmentation of flamenco recordings. Finally, we demonstrate in a data-driven corpus study, how automatic annotations can be mined to discover interesting correlations and gain insights into a largely undocumented genre

Scaling and compressing melodies using geometric similarity measures

Melodic similarity measurement is of key importance in music information retrieval. In this paper, we use geometric matching techniques to measure the similarity between two melodies. We represent music as sets of points or sets of horizontal line segments in the Euclidean plane and propose efficient algorithms for optimization problems inspired in two operations on melodies; linear scaling and audio compression. In the scaling problem, an incoming query melody is scaled forward until the similarity measure between the query and a reference melody is minimized. The compression problem asks for a subset of notes of a given melody such that the matching cost between the selected notes and the reference melody is minimized